It has previously been suggested to use a tray or bin for supporting a stack of sheets of a media in which the uppermost sheet of the stack is advanced to a processing station for printing by a laser printer, for example. Feeding of the sheets of a media from a stack of sheets has been significantly improved by an auto compensating mechanism shown and described in U.S. Pat. No. 5,527,026 to Padget et al, which is incorporated by reference herein.
The auto compensating mechanism of the aforesaid Padget et al patent has utilized a pair of feed rollers, which are not centered with respect to the width of the stack of sheets. In a laser printer using the auto compensating mechanism of the aforesaid Padget et al patent for advancing each sheet in the stack to a processing station, each of the two feed rollers of the auto compensating mechanism of the aforesaid Padget et al patent has been disposed to be vertically aligned with a last sheet restraint pad. Each of the two feed rollers engages one of the last sheet restraint pads after the last sheet is fed.
The last sheet restraint pad has a long, narrow configuration to insure engagement by the vertically aligned feed roller when the tray is empty. When there are only two sheets remaining in the stack, the coefficient of friction between the last sheet restraint pad and the lowermost sheet in the stack enables the feed rollers to advance only the uppermost of the two sheets from the tray.
The location of the last sheet restraint pads in vertical alignment with the feed rollers has enabled very satisfactory feeding of sheets having a width for which the auto compensating mechanism is designed. However, this arrangement has prevented automatic feeding of narrow sheets from a stack, particularly where one of the last sheet restraint pads and the cooperating feed roller are positioned so that the feed roller could engage the last sheet restraint pad near the end of the feeding of the stack of sheets but before feeding is completed. That is, when the stack is relatively shallow, the feed roller, which is exterior of the periphery of the narrow width sheets of the stack, would engage the last sheet restraint pad. This would result in feeding of the narrow width sheets being stopped.
Accordingly, when automatically feeding various types of sheets of card stock in which it is desired to have a narrower width portion on which printing is to occur than the designed width of the tray, for example, it has been necessary to form the sheet of card stock of the same width as that for which the auto compensating mechanism of the aforesaid Padget et al patent is designed. That is, with 81/2" by 11" paper being the designed size, for example, the sheet of the card stock would have to be this size with the portion in which printing is to occur having its periphery defined by perforations in the sheet. The perforations enable the removal of the printed portion from the remainder of the sheet of card stock after completion of printing following feeding of the sheet of card stock from the stack to a printer.
This is a significant waste of each sheet of media in addition to increasing the material cost. It also increases the production cost of each of the printed portions because of formation of the perforations in the card stock prior to loading in the tray. It also requires a person to remove the printed portion of the card stock from the remainder of the sheet of card stock after printing has occurred.
While manual feeding of narrow sheets of a media to a laser printer may be utilized, manual feeding of a large quantity of sheets is very time consuming because each sheet must be individually fed. Therefore, a card stock of narrow width has not been used with manual feeding since this is a more costly employee expense than to use a sheet of card stock of a standard size and have the previously described perforations formed around the portion to be printed. This same problem exists with other narrow width media such as labels, for example.